Bidirectional hybrid Battery/Ultracapacitor Energy Storage Systems for next generation MVDC shipboard power systems

This paper presents a hybrid Battery/Ultracapacitor Energy Storage System (BUCESS) for next generation shipboard systems. A new configuration of the battery and ultracapacitor combined system is introduced for propulsion systems and pulse power loads. The batteries and ultracapacitors are charged and discharged at high power levels through a dual active bridge and a bidirectional double-boost converter. The converters are optimally designed to control the bidirectional power flow for batteries and ultracapacitors, independently, and to ensure constant voltage regulation of ultracapacitors during charging and discharging. The design guidelines and control schemes are provided for the proposed new topology. Finally, a double-input BUCESS unit is designed, analyzed and simulated to investigate different operation modes of the hybrid energy storage system.